diff --git a/config.lua b/config.lua
index dce1815..accbf81 100644
--- a/config.lua
+++ b/config.lua
@@ -83,5 +83,7 @@ cfg.enable_network = not cfg.playable_mode
 
 assert(not cfg.ars_lips or cfg.unperturbed_trial,
        "cfg.unperturbed_trial must be true to use cfg.ars_lips")
+assert(not cfg.ars_lips or cfg.negate_trials,
+       "cfg.negate_trials must be true to use cfg.ars_lips")
 
 return cfg
diff --git a/main.lua b/main.lua
index add137f..37668f9 100644
--- a/main.lua
+++ b/main.lua
@@ -14,9 +14,9 @@ local trial_neg = true
 local trial_noise = {}
 local trial_rewards = {}
 local trials_remaining = 0
-local mom1  -- first moments in AMSgrad.
-local mom2  -- second moments in AMSgrad.
-local mom2max  -- running element-wise maximum of mom2.
+local mom1 -- first moments in AMSgrad.
+local mom2 -- second moments in AMSgrad.
+local mom2max -- running element-wise maximum of mom2.
 
 local trial_frames = 0
 local total_frames = 0
diff --git a/nn.lua b/nn.lua
index eac6dbf..bb3e828 100644
--- a/nn.lua
+++ b/nn.lua
@@ -67,9 +67,8 @@ local function arange(n, out)
     return out
 end
 
-local function allocate(t, out, init)
+local function allocate(size, out, init)
     out = out or {}
-    local size = t
     if init ~= nil then
         return init(zeros(size, out))
     else
diff --git a/util.lua b/util.lua
index a5d5c7f..735c047 100644
--- a/util.lua
+++ b/util.lua
@@ -8,7 +8,7 @@ local min = math.min
 local pairs = pairs
 local random = math.random
 local select = select
-local sqrt=  math.sqrt
+local sqrt = math.sqrt
 
 local function signbyte(x)
     if x >= 128 then x = 256 - x end